Light emitting device

ABSTRACT

A light emitting device according to the embodiment includes a first electrode; a light emitting structure including a first semiconductor layer over the first electrode, an active layer over the first semiconductor layer, and a second semiconductor layer over the second semiconductor layer; a second electrode over the second semiconductor layer; and a connection member having one end making contact with the first semiconductor layer and the other end making contact with the second semiconductor layer to form a schottky contact with respect to one of the first and second semiconductor layers.

The present application claims priority under 35 U.S.C. §119(a) ofKorean Patent Application No. 10-2009-0118901 filed on Dec. 3, 2009,which is hereby incorporated by reference in its entirety.

BACKGROUND

The embodiment relates to a light emitting device.

A light emitting diode (LED) is a semiconductor light emitting devicethat converts current into light. The LED has been expensively used as alight source for a display device, a vehicle, or a lighting device. Inaddition, the LED can represent a white color having superior lightefficiency by employing a molding member including luminescent materialsor combining LEDs having various colors.

The LED is weak against the ESD (electrostatic discharge) or the surgephenomenon, so the improvement thereof is required.

SUMMARY

The embodiment provides a light emitting device having a novelstructure.

The embodiment provides a light emitting device capable of preventingthe ESD or surge phenomenon.

The embodiment provides a light emitting device capable of bypassing acurrent path when the ESD or surge phenomenon occurs.

The embodiment provides a light emitting device capable of improving thelight emitting efficiency.

The embodiment provides a light emitting device capable of minimizingthe defect rate while improving the reliability thereof.

A light emitting device according to the embodiment may include a firstelectrode; a light emitting structure including a first semiconductorlayer over the first electrode, an active layer over the firstsemiconductor layer, and a second semiconductor layer over the activelayer; a second electrode over the second semiconductor layer; and aconnection member electrically connected to the second electrode anddisposed between the second semiconductor layer and the firstsemiconductor layer while forming a schottky contact with the firstsemiconductor layer.

A light emitting device according to the embodiment may include a firstelectrode including a support member having conductivity; a lightemitting structure including a first semiconductor layer, an activelayer, and a second semiconductor layer over the first electrode; asecond electrode over the second semiconductor layer; a connectionmember disposed between the first and second semiconductor layers andcontacting the first and second semiconductor layers, while theconnection member forms a schottky contact with one of the first andsecond semiconductor layers; an insulating member between a lateral sideof the light emitting structure and the connection member; and apassivation layer over the lateral side of the light emitting structure.

A light emitting device according to the embodiment may include a firstelectrode including a support member having conductivity; a reflectivelayer over the first electrode; a protective layer along an outerperipheral portion of a top surface of the reflective layer; an ohmiccontact layer over the top surface of the reflective layer and an insideside of the protective layer; a light emitting structure including afirst semiconductor layer, an active layer, and a second semiconductorlayer over the ohmic contact layer and the protective layer; a secondelectrode over the second semiconductor layer; a connection memberelectrically connected to the second electrode and disposed between thefirst and second semiconductor layers while forming a schottky contactwith the first semiconductor layer; and an insulating member between alateral side of the light emitting structure and the connection member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a light emitting device according tothe first embodiment;

FIG. 2 is a plan view showing a light emitting device;

FIGS. 3 to 9 are sectional views showing the manufacturing procedure fora light emitting device according to the first embodiment;

FIG. 10 is a sectional view showing a light emitting device according toanother embodiment;

FIG. 11 is a sectional view showing a light emitting device according tothe second embodiment;

FIG. 12 is a sectional view showing a light emitting device according tothe third embodiment;

FIG. 13 is a sectional view showing a light emitting device according tothe fourth embodiment;

FIG. 14 is a sectional view showing a light emitting device according tothe fifth embodiment;

FIG. 15 is a sectional view showing a light emitting device packageincluding a light emitting device according to the embodiment;

FIG. 16 is an exploded perspective view of a display device according tothe embodiment;

FIG. 17 is a sectional view showing a display device according to theembodiment; and

FIG. 18 is a perspective view showing a lighting device according to theembodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the description of the embodiments, it will be understood that, whena layer (or film), a region, a pattern, or a structure is referred to asbeing “on” or “under” another substrate, another layer (or film),another region, another pad, or another pattern, it can be “directly” or“indirectly” on the other substrate, layer (or film), region, pad, orpattern, or one or more intervening layers may also be present. Such aposition of the layer has been described with reference to the drawings.

Hereinafter, embodiments will be described with reference accompanyingdrawings. The thickness and size of each layer shown in the drawings maybe exaggerated, omitted or schematically drawn for the purpose ofconvenience or clarity. In addition, the size of elements does notutterly reflect an actual size.

FIG. 1 is a sectional view showing a light emitting device according tothe first embodiment, and FIG. 2 is a plan view of the light emittingdevice shown in FIG. 1.

Referring to FIGS. 1 and 2, the light emitting device 1 includes a firstelectrode 170, a reflective layer 160, a protective layer 158, an ohmiccontact layer 155, a first conductive semiconductor layer 150, an activelayer 140, a second conductive semiconductor layer 130, a secondelectrode 180, a connection member 185 and an insulating member 145. Forinstance, the first conductive semiconductor layer 150, the active layer140, and the second conductive semiconductor layer 130 may include thegroup III-V compound semiconductor and constitute a light emittingstructure.

The first electrode 170 has a function for supporting layers formedthereon as well as a function as an electrode. In other words, the firstelectrode 170 may include a support member having conductivity.

The first electrode 118 may include at least one selected from the groupconsisting of Ti, Cr, Ni, Al, Pt, Au, W, Cu and Mo or a semiconductorsubstrate doped with impurities, but the embodiment is not limitedthereto.

The first electrode 170 can be plated and/or deposited under the lightemitting structure or be attached in the form of a sheet, but theembodiment is not limited thereto.

The first electrode 170 supports the light emitting structure andsupplies power, together with the second electrode 180, to the lightemitting device 1.

The reflective layer 160 may be formed on the first electrode 170. Thereflective layer 160 can be prepared by using at least one selected fromthe group consisting of Ag, Al, Pt, and an alloy thereof having thehigher reflectivity, but the embodiment is not limited thereto.

The reflective layer 160 reflects light emitted from the light emittingstructure, thereby improving the light extraction efficiency of thelight emitting device 1.

An adhesion layer (not shown) including Ni or Ti can be formed betweenthe reflective layer 160 and the first electrode 170 to improve aninterfacial adhesive property therebetween.

The protective layer 158 can be formed along an outer peripheral portionof the light emitting structure. The protective layer 158 may include atleast one selected from the group consisting of SiO₂, Si_(x)O_(y),Si₃N₄, Si_(x)N_(y), SiO_(x)N_(y), Al₂O₃, TiO₂, ITO, AZO, and ZnO, butthe embodiment is not limited thereto.

The protective layer 158 prevents the light emitting structure frommaking contact with the first electrode 170, thereby preventing theelectric short.

The ohmic contact layer 155 may be formed on the top surface of thereflective layer 160 and an inside side of the protective layer 158. Theohmic contact layer 155 may include at least one selected from the groupconsisting of Ni, Pt, Ir, Rh, and Ag, but the embodiment is not limitedthereto. The ohmic contact layer 155 may further include at least oneselected from the group consisting of ITO (indium tin oxide), IZO(indium zinc oxide), IZTO (indium zinc tin oxide), IAZO (indium aluminumzinc oxide), IGZO (indium gallium zinc oxide), IGTO (indium gallium tinoxide), AZO (aluminum zinc oxide), ATO (antimony tin oxide), or GZO(gallium zinc oxide), but the embodiment is not limited thereto.

The ohmic contact layer 155 may minimize the ohmic contact resistancebetween the first conductive semiconductor layer 150 and the reflectivelayer 160. In addition, the ohmic contact layer 155 may include apattern to improve the current spreading of the light emitting device 1.

The first conductive semiconductor layer 150 may be formed on the ohmiccontact layer 155 and the protective layer 158. For instance, the firstconductive semiconductor layer 150 includes a p type semiconductor layerdoped with the p type dopant. The p type semiconductor layer may includea semiconductor material having the compositional formula ofIn_(x)Al_(y)Ga_(1-x-y)N (0≦x≦1, 0≦y≦1, 0≦x≦1), such as at least oneselected from the group consisting of InAlGaN, GaN, AlGaN, InGaN, AlN,or InN. In addition, the p type semiconductor layer may be doped with ptype dopant such as Mg, Zn, Ca, Sr, or Ba.

The active layer 140 can be formed on the first conductive semiconductorlayer 150. The active layer 140 emits the light through therecombination of electrons (or holes) injected through the secondconductive semiconductor layer 130 with holes (or electrons) injectedthrough the first conductive semiconductor layer 150. The wavelength ofthe light, which determines the color of the light, may vary dependingon the intrinsic material for the active layer 140. That is, the bandgapof energy band is determined according to the intrinsic material of theactive layer 140 and the active layer 140 emits the light having thewavelength corresponding to bandgap difference.

The active layer 140 may have the single quantum well structure, the MQW(multiple quantum well) structure, the quantum wire structure or thequantum dot structure, but the embodiment is not limited thereto.

If the active layer 140 has the MQW structure, the active layer 140 isprepared as a stack structure including a plurality of well layers andbarrier layers. For instance, the active layer 140 may have the stackstructure of an InGaN well layer/a GaN barrier layer.

A clad layer (not shown) doped with the n type or p type dopant can beformed on and/or under the active layer 140. The clad layer may includean AlGaN layer or an InAlGaN layer.

The second conductive semiconductor layer 130 may be formed on theactive layer 140. For instance, the second conductive semiconductorlayer 130 may include an n type semiconductor layer including an n typedopant. The n type semiconductor layer may include a semiconductormaterial having the compositional formula of In_(x)Al_(y)Ga_(1-x-y)N(0≦x≦1, 0≦y≦1, 0≦x+y≦1). For instance, the n type semiconductor layermay include one selected from the group consisting of InAlGaN, GaN,AlGaN, InGaN, AlN, and InN. In addition, the n type semiconductor layermay be doped with n type dopant, such as Si, Ge or Sn.

The second conductive semiconductor layer 130 may include a p typesemiconductor layer and the first conductive semiconductor layer 150 mayinclude an n type semiconductor layer. In addition, other conductivesemiconductor layers (not shown) and the active layer can be formed onthe second conductive semiconductor layer 130. Thus, the light emittingdevice 1 may have one of NP, PN, NPN and PNP junction structures, butthe embodiment is not limited thereto.

The second electrode 180 is formed on the top surface of the secondconductive semiconductor layer 130. The second electrode 180, togetherwith the first electrode 170, supplies power to the light emittingdevice 1. For instance, the second electrode 180 includes at least oneselected from the group consisting of Al, Ti and Cr, but the embodimentis not limited thereto.

The second conductive semiconductor layer 130 is formed on the topsurface thereof with a concavo-convex structure to improve the lightextraction efficiency of the light emitting device 1.

The light emitting structure may include a groove 135. The groove 135can be locally formed in the light emitting structure. The groove 135has a predetermined size and is recessed downward of the light emittingstructure in the form of a dent. When viewed from the top, the groove135 has a triangular shape, a rectangular shape, a polygonal shape, acircular shape, or an oval shape, but the embodiment is not limitedthereto. The groove 135 can be formed through the etching or laserdrilling process. The groove 135 extends through the second conductivesemiconductor layer 130 and the active layer 140 and the firstconductive semiconductor layer 150 is partially removed by the groove135 so that the first conductive semiconductor layer 150 is exposedthrough the groove 135. However, the embodiment may not limit themanufacturing method and the shape of the groove 135.

The connection member 185 may be formed along the groove 135. That is,the connection member 185 can be formed at the lateral sides of thesecond conductive semiconductor layer 130, the active layer 140 and thefirst conductive semiconductor layer 150 formed in the groove 135. Oneend 186 of the connection member 185 makes contact with the secondconductive semiconductor layer 130 and the other end 187 of theconnection member 185 makes contact with the first conductivesemiconductor layer 150. One end 186 of the connection member 185 can beintegrally formed with the second electrode 180, but the embodiment isnot limited thereto.

The connection member 185 can be formed through at least one of theplating process and the deposition process, but the embodiment is notlimited thereto.

The connection member 185 may be electrically connected to the secondelectrode 180 while being disposed between the second conductivesemiconductor layer 130 and the first conductive semiconductor layer150. In addition, the connection member 185 makes schottky contact withthe first conductive semiconductor layer 150. In other words, theconnection member 185 makes contact with the second conductivesemiconductor layer 130 and the first conductive semiconductor layer150, respectively, and forms a schottky contact with one of the secondconductive semiconductor layer 130 and the first conductivesemiconductor layer 150 and to form an ohmic contact with the other oneof the second conductive semiconductor layer 130 and the firstconductive semiconductor layer 150. According to the embodiment, theohmic contact is formed between the connection member 185 and the secondconductive semiconductor layer 130, and the schottky contact is formedbetween the connection member 185 and the first conductive semiconductorlayer 150.

The connection member 185 may include at least one selected from thegroup consisting of Al, Ti and Cr to form the schottky contact with thefirst conductive semiconductor layer 150.

If the connection member 185 may include the above metal, one end 186 ofthe connection member 185 makes contact with the second conductivesemiconductor layer 130 while forming the ohmic contact, and the otherend 187 of the connection member 185 makes contact with the firstconductive semiconductor layer 150 while forming the schottky contact.

A potential barrier may be generated at a contact interface 138 betweenthe other end 187 of the connection member 185 and the first conductivesemiconductor layer 150 because high resistance occurs at the contactinterface 138 due to the schottky contact. The contact interface 138 mayinclude a concavo-convex structure, which is formed by processing thetop surface of the first conductive semiconductor layer 150 formed inthe groove 135, such that high resistance can be generated by theschottky contact. That is, a high potential barrier may be generatedbetween the connection member 185 and the first conductive semiconductorlayer 150 through the schottky contact due to the concavo-convexstructure.

In detail, the potential barrier higher than the operational voltage forthe light emitting device 1 may be generated at the contact interface138. Thus, the voltage higher than the potential barrier must be appliedto allow current to flow through the first conductive semiconductorlayer 150. For instance, the potential barrier is in the range of 4V to6V. The potential barrier may vary depending on the design rule of thelight emitting device 1 and the embodiment is not limited thereto.

Since the potential barrier is higher than the operational voltage forthe light emitting device 1, if the forward voltage is applied to thelight emitting device 1, the current may not flow through the contactinterface 138, but flow through the light emitting structure, so thatthe light emitting device 1 emits the light.

In contrast, if the reverse voltage higher than the potential barrier isapplied to the light emitting device 1, for example, if the voltagehigher than the potential barrier is applied to the light emittingdevice 1 due to the ESD or the surge phenomenon, the current may flowthrough the contact interface 138, and then flow through the ohmiccontact layer 155 and the first electrode 170 by way of the firstconductive semiconductor layer 150, so that the light emitting structurecan be protected from the high voltage derived from the ESD or the surgephenomenon.

The insulating member 145 may be formed between an inner wall of thegroove 135 and the connection member 135. The insulating member 145 isformed at both lateral sides of the second conductive semiconductorlayer 130, the active layer 140 and the first conductive semiconductorlayer 150 formed in the groove 135. In addition, the insulating member145 can be formed on a portion of the top surface of the firstconductive semiconductor layer 150. The connection member 185 covers atleast a portion of the insulating member 145 between one end 186 and theother end 187 of the connection member 185. That is, one end 186 of theconnection member 185 makes contact with the second conductivesemiconductor layer 130 while being integrally formed with the secondelectrode 180 and the other end 187 of the connection member 185 makescontact with the first conductive semiconductor layer 150 to cover atleast a portion of the insulating member 145. The insulating member 145prevents the connection member 185 and each layer of the light emittingstructure from being subject to the electric short.

Meanwhile, as shown in FIG. 1, the insulating member 145 is formed atthe inner wall of the groove 135 except for the contact interface 138,but the embodiment is not limited thereto.

For instance, the insulating member may include at least one selectedfrom the group consisting of SiO₂, Si_(x)O_(y), Si₃N₄, Si_(x)N_(y),SiO_(x)N_(y), Al₂O₃, and TiO₂.

Referring to FIGS. 1 and 10, a first region A of the light emittingstructure where the connection member 185 is not formed can be removed.Since the second conductive semiconductor layer 130 is separated andinsulated by the groove 135, the first region A may not contribute forthe light emission of the active layer 140, so the effect of theembodiment can be achieved even if the first region A is removed.

Hereinafter, the method of manufacturing the light emitting deviceaccording to the embodiment will be described in detail with referenceto FIGS. 3 to 9. In the following description, details of the elementsor structures that have been previously described will be omitted inorder to avoid redundancy. In addition, it is assumed that the lightemitting structure is formed under the substrate 110 to facilitate theexplanation.

FIGS. 3 to 9 are sectional views showing the manufacturing procedure forthe light emitting device according to the first embodiment.

Referring to FIG. 3, the light emitting structure is formed on thesubstrate 110.

That is, the second conductive semiconductor layer 130 is formed on thesubstrate 110, the active layer 140 is formed on the second conductivesemiconductor layer 130, and the first conductive semiconductor layer150 is formed on the active layer 140.

In addition, a non-conductive semiconductor layer including group II toVI compound semiconductors and/or a buffer layer can be formed betweenthe second conductive semiconductor layer 130 and the substrate 110, butthe embodiment is not limited thereto.

The substrate 110 may include at least one selected from the groupconsisting of Al₂O₃, SiC, Si, GaAs, GaN, ZnO, GaP, InP, and Ge.

Referring to FIG. 4, the protective layer 158 is formed along an outerperipheral portion of the first conductive semiconductor layer 150. Theprotective layer 158 can be formed through the deposition process, butthe embodiment is not limited thereto.

The protective layer 158 may include at least one selected from thegroup consisting of SiO₂, Si_(x)O_(y), Si₃N₄, Si_(x)N_(y), SiO_(x)N_(y),Al₂O₃, TiO₂, ITO, AZO, and ZnO.

Referring to FIG. 5, the ohmic contact layer 155 is formed on the topsurface of the first conductive semiconductor layer 150 and the innerportion of the protective layer 158. The reflective layer 160 is formedon the ohmic contact layer 155 and the protective layer 158. Inaddition, the first electrode 170 is formed on the reflective layer 160.

If the reflective layer 160 has the function of minimizing the ohmiccontact resistance, the ohmic contact layer 155 may be omitted, and theembodiment is not limited thereto.

Referring to FIG. 6, the resultant structure is turned over such thatthe substrate 110 is disposed at the uppermost layer and the substrate110 is removed from the second conductive semiconductor 130.

The substrate 110 can be removed through the LLO (laser lift off) schemeand/or the etching scheme, but the embodiment is not limited thereto.

After the substrate 110 has been removed, the surface of the secondconductive semiconductor layer 130 is partially removed through theetching process, or the buffer layer (not shown) and/or thenon-conductive semiconductor layer (not show) is removed from the firstconductive semiconductor layer 150, but the embodiment is not limitedthereto.

Referring to FIG. 7, the light emitting structure is subject to the mesaetching process, so that the mesa structure is formed at the lateralside of the light emitting structure.

Then, the etching process and/or the laser process is performed to formthe groove 135 through the second conductive semiconductor layer 130 andthe active layer 140 such that the first conductive semiconductor layer150 can be exposed, but the embodiment is not limited thereto.

Referring to FIG. 8, the insulating member 145 is formed at the innerwall of the groove 135 except for the contact interface 138. Theinsulating member 145 insulates the light emitting structure from theconnection member 185 which will be formed in the subsequent process.The insulating member 145 is formed at both lateral sides of the secondconductive semiconductor layer 130, the active layer 140 and the firstconductive semiconductor layer 150 in the groove 135. In addition, theinsulating member 145 is formed on a portion of the top surface of thefirst conductive semiconductor layer 150. Further, the insulating member145 is formed on a portion of the second conductive semiconductor layer130 in the vicinity of the groove 135.

The insulating member 145 can be formed through the deposition process,but the embodiment is not limited thereto.

The insulating member 145 may include at least one selected from thegroup consisting of SiO₂, Si_(x)O_(y), Si₃N₄, Si_(x)N_(y), SiO_(x)N_(y),Al₂O₃, and TiO₂.

Referring to FIG. 9, the second electrode 180 is formed on the secondconductive semiconductor layer 130. In addition, the connection member185 is formed along the groove 135. One end 186 of the connection member185 makes contact with the second conductive semiconductor layer 130 andthe other end 187 of the connection member 185 makes contact with thefirst conductive semiconductor layer 150 through the contact interface138. The connection member 185 can be integrally formed with the secondelectrode 180.

The connection member 185 can be formed through at least one of theplating process and the deposition process, but the embodiment is notlimited thereto.

The connection member 185 makes contact with the second conductivesemiconductor layer 130 and the first conductive semiconductor layer 150to form a schottky contact with respect to one of the second conductivesemiconductor layer 130 and the first conductive semiconductor layer 150and to form an ohmic contact with respect to the other of the secondconductive semiconductor layer 130 and the first conductivesemiconductor layer 150. The connection member 185 may include at leastone selected from the group consisting of Al, Ti and Cr, but theembodiment is not limited thereto.

In detail, the potential barrier higher than the operational voltage forthe light emitting device 1 may be generated at the contact interface138. Thus, the voltage higher than the potential barrier must be appliedto allow current to flow through the first conductive semiconductorlayer 150. For instance, the potential barrier is in the range of 4V to6V. The potential barrier may vary depending on the design rule of thelight emitting device 1 and the embodiment is not limited thereto.

Since the potential barrier is higher than the operational voltage forthe light emitting device 1, if the forward voltage is applied to thelight emitting device 1, the current may not flow through the contactinterface 138, but flow through the light emitting structure, so thatthe light emitting device 1 emits the light.

In contrast, if the reverse voltage higher than the potential barrier isapplied to the light emitting device 1, for example, if the voltagehigher than the potential barrier is applied to the light emittingdevice 1 due to the ESD or the surge phenomenon, the current may flowthrough the contact interface 138, and then flow through the ohmiccontact layer 155 and the first electrode 170 by way of the firstconductive semiconductor layer 150, so that the light emitting structurecan be protected from the high voltage derived from the ESD or the surgephenomenon.

The second conductive semiconductor layer 130 is formed on the topsurface thereof with the concavo-convex structure to improve the lightextraction efficiency of the light emitting device 1.

Hereinafter, a light emitting device and a method of manufacturing thelight emitting device according to the second embodiment will bedescribed. In the following description of the second embodiment,details of the elements or structures that have been previouslydescribed in the first embodiment will be omitted in order to avoidredundancy.

The light emitting device 2 according to the second embodiment isidentical to the light emitting device 1 according to the firstembodiment, except that the second electrode 180 is spaced apart fromthe connection member 185.

FIG. 11 is a view showing the light emitting device according to thesecond embodiment.

Referring to FIG. 11, the light emitting device 2 includes a firstelectrode 170, a reflective layer 160, a protective layer 158, an ohmiccontact layer 155, a first conductive semiconductor layer 150, an activelayer 140, a second conductive semiconductor layer 130, a secondelectrode 180, a connection member 185 and an insulating member 145.

The second electrode 180 can be formed on the second conductivesemiconductor layer 130.

The connection member 185 is formed along the groove 135. One end 186 ofthe connection member 185 makes contact with the second conductivesemiconductor layer 130 and the other end 187 of the connection member185 makes contact with the first conductive semiconductor layer 150.

The second electrode 180 is spaced apart from one end 186 of theconnection member 185. In addition, the second electrode 180 iselectrically insulated from one end 186 of the connection member 185.Although the second electrode 180 is spaced apart from the connectionmember 185, since the second conductive semiconductor layer 130 hasconductivity, the connection member 185 can protect the light emittingdevice 2 from the ESD or the surge phenomenon. In detail, when the highvoltage derived from the ESD or the surge phenomenon is applied to thesecond electrode 180, since the second conductive semiconductor layer130 has conductivity, a current path is formed among the secondelectrode 180, the second conductive semiconductor layer 130, theconnection member 185, the first conductive semiconductor layer 150, theohmic contact layer 155, the reflective layer 160 and the firstelectrode 170, so that the light emitting structure can be preventedfrom being broken by the high reverse voltage derived from the ESD orthe surge phenomenon. If the current path is not formed, the lightemitting structure may be broken due to the high reverse voltage derivedfrom the ESD or the surge phenomenon.

Hereinafter, a light emitting device and a method of manufacturing thelight emitting device according to the third embodiment will bedescribed. In the following description of the third embodiment, detailsof the elements or structures that have been previously described in thefirst embodiment will be omitted in order to avoid redundancy.

The light emitting device according to the third embodiment is identicalto the light emitting device according to the first embodiment exceptthat the connection member is formed along the outer peripheral portionof the light emitting structure.

FIG. 12 is a sectional view showing the light emitting device accordingto the third embodiment.

Referring to FIG. 12, the light emitting device 3 includes a firstelectrode (not shown), a reflective layer (not shown), a protectivelayer 158, an ohmic contact layer (not shown), a first conductivesemiconductor layer 150, an active layer 140, a second conductivesemiconductor layer 130, a second electrode 180, a connection member 185a and an insulating member 145 a. The first conductive semiconductorlayer 150, the active layer 140, and the second conductive semiconductorlayer 130 may constitute a light emitting structure.

A groove 135 a is formed along an outer peripheral portion of the lightemitting structure. The groove 135 a has the depth and shape identicalto those of the groove 135 according to the first embodiment, but theembodiment is not limited thereto.

The groove 135 a can be formed through the etching or laser drillingprocess. The groove 135 a extends through the second conductivesemiconductor layer 130 and the active layer 140 and the firstconductive semiconductor layer 150 is partially removed by the groove135 a so that the first conductive semiconductor layer 150 is exposedthrough the groove 135 a.

A contact interface can be formed between the exposed first conductivesemiconductor layer 150 and the connection member 185 a. In detail, thecontact interface is formed along the outer peripheral portion of thelight emitting structure. The contact interface may have theconcavo-convex structure, which is formed by processing the top surfaceof the first conductive semiconductor layer 150 using oxygen or nitrogenplasma, but the embodiment is not limited thereto.

The connection member 185 a can be formed along the groove 135 in such amanner that one end 186 a of the connection member 185 a makes contactwith the second conductive semiconductor layer 130 and the other end 187a of the connection member 185 a makes contact with the first conductivesemiconductor layer 150 through the contact interface. The contactinterface, which makes contact with the other end 187 a of theconnection member 185 a, is formed along the groove 135 a so that thecontact interface may have an area as large as possible. Thus, when thehigh reverse voltage is applied due to the ESD or the surge phenomenon,the current path is distributed so that the ESD or the surge phenomenoncan be rapidly blocked. Thus, the breakage of the light emittingstructure caused by the ESD or the surge phenomenon can be minimized.

Hereinafter, a light emitting device and a method of manufacturing thelight emitting device according to the fourth embodiment will bedescribed. In the following description of the fourth embodiment,details of the elements or structures that have been previouslydescribed in the first embodiment will be omitted in order to avoidredundancy.

The light emitting device 4 according to the fourth embodiment isidentical to the light emitting device 1 according to the firstembodiment except that a current blocking layer 153 is formed betweenthe ohmic contact layer 155 and the first conductive semiconductor layer150.

FIG. 13 is a sectional view showing the light emitting device 4according to the fourth embodiment.

Referring to FIG. 13, the light emitting device 4 includes a firstelectrode 170, a reflective layer 160, a protective layer 158, an ohmiccontact layer 155, a current blocking layer 153, a first conductivesemiconductor layer 150, an active layer 140, a second conductivesemiconductor layer 130, a second electrode 180, a connection member 185and an insulating member 145.

The current blocking layer 153 is formed between the ohmic contact layer155 and the second conductive semiconductor layer 130. At least aportion of the current blocking layer 153 may overlap with the secondelectrode 180 in the vertical direction.

Therefore, the current blocking layer 153 prevents the current frombeing concentrated within the shortest distance between the first andsecond electrodes 170 and 180, thereby improving the light emittingefficiency of the light emitting device 4. Since the current blockinglayer 154 interferes with the current flow, the current may not flowthrough the current blocking layer 153. Thus, the current verticallyflowing between the first and second electrodes 170 and 180 mayinterfere with the current blocking layer 153, so that the current isdistributed into the ohmic contact layer 155 adjacent to the currentblocking layer 153.

The current blocking layer 153 includes a material having the electricinsulating property or forming the schottky contact with respect to thefirst conductive semiconductor layer 150, but the embodiment is notlimited thereto. For instance, the current blocking layer 153 mayinclude at least one selected from the group consisting of ZnO, SiO₂,SiO_(x), SiO_(x)N_(y), Si₃N₄, Al₂O₃, TiO_(x), Ti, Al, and Cr, but theembodiment is not limited thereto.

Hereinafter, a light emitting device and a method of manufacturing thelight emitting device according to the fifth embodiment will bedescribed. In the following description of the fifth embodiment, detailsof the elements or structures that have been previously described in thefirst embodiment will be omitted in order to avoid redundancy.

The light emitting device 5 according to the fifth embodiment isidentical to the light emitting device 1 according to the firstembodiment except that a passivation layer 190 is formed on at least oneside of the light emitting structure that emits the light.

FIG. 14 is a sectional view showing the light emitting device accordingto the fifth embodiment.

Referring to FIG. 14, the light emitting device 5 includes a firstelectrode 170, a reflective layer 160, a protective layer 158, an ohmiccontact layer 155, a first conductive semiconductor layer 150, an activelayer 140, a second conductive semiconductor layer 130, a secondelectrode 180, a connection member 185, an insulating member 145, and apassivation layer 190.

The first conductive semiconductor layer 130, the active layer 140 andthe second conductive semiconductor layer 150 may constitute the lightemitting structure including group III to V compound semiconductormaterials that emit the light.

The passivation layer 190 can be formed on at least a side of the lightemitting structure. In detail, one end of the passivation layer 190 isformed on the top surface of the light emitting structure, that is, onthe insulating member 145. In addition, the other end of the passivationlayer 190 extends onto the protective layer 158 along the lateral sideof the light emitting structure.

The passivation layer 190 may prevent the electric short from occurringbetween the light emitting structure and the external electrode, therebyminimizing the defect rate of the light emitting device 5 and improvingthe reliability of the light emitting device 5.

For instance, the passivation layer 190 includes at least one selectedfrom the group consisting of ZnO, SiO₂, SiO_(x), SiO_(x)N_(y), Si₃N₄,Al₂O₃, and TiO_(x). The passivation layer 190 can be prepared as anoxide layer by thermo-chemically oxidizing the light emitting structure,but the embodiment is not limited thereto.

FIG. 15 is a sectional view showing a light emitting device packageincluding the light emitting device according to the embodiments.

Referring to FIG. 15, the light emitting device package 30 includes abody 20, first and second electrode layers 31 and 32 formed on the body20, the light emitting device 1 provided on the body 20 and electricallyconnected to the first and second electrode layers 31 and 32 and amolding member 40 that surrounds the light emitting device 1.

The body 20 may include silicon, synthetic resin or metallic material.When viewed from the top, the body 20 has a cavity 50 formed with aninclined inner wall 53.

The first and second electrode layers 31 and 32 are electricallyisolated from each other and formed by passing through the body 20. Indetail, one ends of the first and second electrode layers 31 and 32 aredisposed in the cavity 50 and the other ends of the first and secondelectrode layers 31 and 32 are attached to an outer surface of the body20 and exposed to the outside.

The first and second electrode layers 31 and 32 supply power to thelight emitting device and improve the light efficiency by reflecting thelight emitted from the light emitting device 1. Further, the first andsecond electrode layers 31 and 32 dissipate heat generated from thelight emitting device 1 to the outside.

The light emitting device 1 can be installed on the body 20 or the firstor second electrode layer 31 or 32.

First and second wires 171 and 181 of the light emitting device 1 can beelectrically connected to one of the first and second electrode layers31 and 32, but the embodiment is not limited thereto.

The molding member 40 surrounds the light emitting device 1 to protectthe light emitting device 1. In addition, the molding member 40 mayinclude luminescent materials to change the wavelength of the lightemitted from the light emitting device 1.

The light emitting device or the light emitting device package accordingto the embodiment can be applied to the light unit. The light unitincludes a plurality of light emitting devices or a plurality of lightemitting device packages. The light unit may include the display deviceas shown in FIGS. 16 and 17 and the lighting device as shown in FIG. 18.In addition, the light unit may include a lighting lamp, a signal lamp,a headlight of a vehicle, and an electric signboard.

FIG. 16 is an exploded perspective view showing the display deviceaccording to the embodiment.

Referring to FIG. 16, the display device 1000 includes a light guideplate 1041, a light emitting module 1031 for supplying the light to thelight guide plate 1041, a reflective member 1022 provided below thelight guide plate 1041, an optical sheet 1051 provided above the lightguide plate 1041, a display panel 1061 provided above the optical sheet1051, and a bottom cover 1011 for receiving the light guide plate 1041,the light emitting module 1031, and the reflective member 1022. However,the embodiment is not limited to the above structure.

The bottom cover 1011, the reflective sheet 1022, the light guide plate1041 and the optical sheet 1051 may constitute a light unit 1050.

The light guide plate 1041 diffuses the light to provide surface light.The light guide plate 1041 may include transparent material. Forinstance, the light guide plate 1041 may include one of acryl-basedresin, such as PMMA (polymethyl methacrylate, PET (polyethyleneterephthalate), PC (polycarbonate), COC (cyclic olefin copolymer) andPEN (polyethylene naphthalate) resin.

The light emitting module 1031 is disposed at one side of the lightguide plate 1041 to supply the light to at least one side of the lightguide plate 1041. The light emitting module 1031 serves as the lightsource of the display device.

At least one light emitting module 1031 is provided to directly orindirectly supply the light from one side of the light guide plate 1041.The light emitting module 1031 may include a substrate 1033 and lightemitting device packages 30 according to the embodiments. The lightemitting device packages 30 are arranged on the substrate 1033 whilebeing spaced apart from each other at the predetermined interval. Thesubstrate 1033 may include a printed circuit board (PCB), but theembodiment is not limited thereto. In addition, the substrate 1033 mayalso include a metal core PCB (MCPCB) or a flexible PCB (FPCB), but theembodiment is not limited thereto. If the light emitting device packages30 are installed on the side of the bottom cover 1011 or on a heatdissipation plate, the substrate 1033 may be omitted. The heatdissipation plate partially makes contact with the top surface of thebottom cover 1011. Thus, the heat generated from the light emittingdevice packages 30 can be emitted to the bottom cover 1011 through theheat dissipation plate.

In addition, the light emitting device packages 30 are arranged suchthat light exit surfaces of the light emitting device packages 30 arespaced apart from the light guide plate 1041 by a predetermineddistance, but the embodiment is not limited thereto. The light emittingdevice packages 30 may directly or indirectly supply the light to alight incident surface, which is one side of the light guide plate 1041,but the embodiment is not limited thereto.

The reflective member 1022 is disposed below the light guide plate 1041.The reflective member 1022 reflects the light, which is traveleddownward through the bottom surface of the light guide plate 1041,toward the display panel 1061, thereby improving the brightness of thedisplay panel 1061. For instance, the reflective member 1022 may includePET, PC or PVC resin, but the embodiment is not limited thereto. Thereflective member 1022 may serve as the top surface of the bottom cover1011, but the embodiment is not limited thereto.

The bottom cover 1011 may receive the light guide plate 1041, the lightemitting module 1031, and the reflective member 1022 therein. To thisend, the bottom cover 1011 has a receiving section 1012 having a boxshape with an opened top surface, but the embodiment is not limitedthereto. The bottom cover 1011 can be coupled with the top cover (notshown), but the embodiment is not limited thereto.

The bottom cover 1011 can be manufactured through a press process or anextrusion process by using metallic material or resin material. Inaddition, the bottom cover 1011 may include metal or non-metallicmaterial having superior thermal conductivity, but the embodiment is notlimited thereto.

The display panel 1061, for instance, is an LCD panel including firstand second transparent substrates, which are opposite to each other, anda liquid crystal layer disposed between the first and second substrates.A polarizing plate can be attached to at least one surface of thedisplay panel 1061, but the embodiment is not limited thereto. Thedisplay panel 1061 displays information by blocking the light generatedfrom the light emitting module 1031 or allowing the light to passtherethrough. The display device 1000 can be applied to various portableterminals, monitors of notebook computers, monitors or laptop computers,and televisions.

The optical sheet 1051 is disposed between the display panel 1061 andthe light guide plate 1041 and includes at least one transmittive sheet.For instance, the optical sheet 1051 includes at least one of adiffusion sheet, a horizontal and vertical prism sheet, and a brightnessenhanced sheet. The diffusion sheet diffuses the incident light, thehorizontal and vertical prism sheet concentrates the incident light ontothe display panel 1061, and the brightness enhanced sheet improves thebrightness by reusing the lost light. In addition, a protective sheetcan be provided on the display panel 1061, but the embodiment is notlimited thereto.

The light guide plate 1041 and the optical sheet 1051 can be provided inthe light path of the light emitting module 1031 as optical members, butthe embodiment is not limited thereto.

FIG. 17 is a sectional view showing a display device according to theembodiment.

Referring to FIG. 17, the display device 1100 includes a bottom cover1152, a substrate 1120 on which the light emitting device packages 30are arranged, an optical member 1154, and a display panel 1155.

The substrate 1120 and the light emitting device packages 30 mayconstitute the light emitting module 1060. In addition, the bottom cover1152, at least one light emitting module 1060, and the optical member1154 may constitute the light unit (not shown).

The bottom cover 1151 can be provided with a receiving section 1153, butthe embodiment is not limited thereto.

The optical member 1154 may include at least one of a lens, a lightguide plate, a diffusion sheet, a horizontal and vertical prism sheet,and a brightness enhanced sheet. The light guide plate may include PC orPMMA (Poly methyl methacrylate). The light guide plate can be omitted.The diffusion sheet diffuses the incident light, the horizontal andvertical prism sheet concentrates the incident light onto the displaypanel 1155, and the brightness enhanced sheet improves the brightness byreusing the lost light.

The optical member 1154 is disposed above the light emitting module 1060in order to convert the light emitted from the light emitting module1060 into the surface light. In addition, the optical member 1154 maydiffuse or collect the light.

FIG. 18 is a perspective view showing a lighting device according to theembodiment.

Referring to FIG. 18, the lighting device 1500 includes a case 1510, alight emitting module 1530 installed in the case 1510, and a connectionterminal 1520 installed in the case 1510 to receive power from anexternal power source.

Preferably, the case 1510 includes material having superior heatdissipation property. For instance, the case 1510 includes metallicmaterial or resin material.

The light emitting module 1530 may include a substrate 1532 and lightemitting device packages 30 installed on the substrate 1532. The lightemitting device packages 30 are spaced apart from each other or arrangedin the form of a matrix.

The substrate 1532 includes an insulating member printed with a circuitpattern. For instance, the substrate 1532 includes a PCB, an MCPCB, anFPCB, a ceramic PCB, and an FR-4 substrate.

In addition, the substrate 1532 may include material that effectivelyreflects the light. A coating layer can be formed on the surface of thesubstrate 1532. At this time, the coating layer has a white color or asilver color to effectively reflect the light.

At least one light emitting device package 30 is installed on thesubstrate 1532. Each light emitting device package 30 may include atleast one LED (light emitting diode) chip. The LED chip may include anLED that emits the light of visible ray band having red, green, blue orwhite color and a UV (ultraviolet) LED that emits UV light.

The light emitting device packages 30 of the light emitting module 1530can be variously combined to provide various colors and brightness. Forinstance, the white LED, the red LED and the green LED can be combinedto achieve the high color rendering index (CRI).

The connection terminal 1520 is electrically connected to the lightemitting module 1530 to supply power to the light emitting module 1530.The connection terminal 1520 has a shape of a socket screw-coupled withthe external power source, but the embodiment is not limited thereto.For instance, the connection terminal 1520 can be prepared in the formof a pin inserted into the external power source or connected to theexternal power source through a wire.

According to the embodiment, the light emitting structure includes thefirst conductive semiconductor layer, the active layer and the secondconductive semiconductor layer. In addition, one end of the connectionmember makes contact with the first conductive semiconductor layer andthe other end of the connection member makes contact with the secondconductive semiconductor layer to form the schottky contact with respectto one of the first and second conductive semiconductor layer. Thus,when the high reverse voltage derived from the ESD or the surgephenomenon is applied to the light emitting structure, the current pathis formed through the first or second conductive semiconductor layerwhich forms the schottky contact with respect to the connection member,so that the light emitting structure can be prevented from being brokenby the high reverse voltage.

According to the embodiment, the light emitting structure includes thegroove, which extends through the second conductive semiconductor layerand the active layer to expose the first conductive semiconductor layer,and the groove has the dent shape. In addition, the first or secondconductive semiconductor layer, which forms the schottky contact withrespect to the connection member, can be formed on the surface thereofwith the contact interface having the concavo-convex structure.Therefore, the connection member is disposed between the first andsecond conductive semiconductor layers and the contact interface isformed on the surface of the first or second conductive semiconductorlayer, so that the current path, which bypasses at least the activelayer, is formed when the high reverse voltage derived from the ESD orthe surge phenomenon is applied to the light emitting structure, therebypreventing the light emitting structure from being broken by the ESD orthe surge phenomenon.

According to the embodiment, the groove is formed along the outerperipheral portion of the light emitting structure, and the first orsecond conductive semiconductor layer, which forms the schottky contactwith respect to the connection member, is formed on the surface thereofwith the contact interface having the concavo-convex structure. Thus,the area of the contact interface can be maximized, so that the currentpath is distributed when the high reverse voltage derived from the ESDor the surge phenomenon is applied to the light emitting structure,thereby rapidly blocking the ESD or the surge phenomenon.

According to the embodiment, one end of the connection member isintegrally formed with the second electrode. Thus, the high reversevoltage supplied to the second electrode caused by the ESD or the surgephenomenon is bypassed to the conductive semiconductor layer, whichforms the schottky contact with respect to the connection member, sothat the light emitting structure can be protected from the ESD or thesurge phenomenon.

The method of manufacturing the light emitting device according to theembodiment includes the steps of preparing the first electrode, formingthe light emitting structure including the first conductivesemiconductor layer, the active layer, and the second conductivesemiconductor layer on the first electrode, forming the second electrodeon the second conductive semiconductor layer, and preparing theconnection member having one end making contact with the firstconductive semiconductor layer and the other end making contact with thesecond conductive semiconductor layer, in which the connection memberforms the schottky contact with respect to one of the first and secondconductive semiconductor layers.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A light emitting device comprising: a first electrode; a lightemitting structure including a first semiconductor layer over the firstelectrode, an active layer over the first semiconductor layer, and asecond semiconductor layer over the active layer; a second electrodeover the second semiconductor layer; and a connection memberelectrically connected to the second electrode and disposed between thesecond semiconductor layer and the first semiconductor layer whileforming a schottky contact with the first semiconductor layer.
 2. Thelight emitting device of claim 1, wherein the light emitting structureincludes a groove, which extends through the second semiconductor layerand the active layer to expose the first semiconductor layer.
 3. Thelight emitting device of claim 2, wherein the groove is locally formedin the light emitting structure and has a dent shape.
 4. The lightemitting device of claim 2, wherein the groove is formed along an outerperipheral portion of the light emitting structure.
 5. The lightemitting device of claim 4, wherein the groove has a dent shape.
 6. Thelight emitting device of claim 1, wherein the connection member isintegrally formed with the second electrode.
 7. The light emittingdevice of claim 2, further comprising an insulating member between thelight emitting structure and the connection member at a lateral side ofthe groove.
 8. The light emitting device of claim 7, wherein theinsulating member is disposed at lateral sides of the secondsemiconductor layer, the active layer, and the first semiconductorlayer, respectively.
 9. The light emitting device of claim 1, whereinthe first semiconductor layer includes a contact interface having aconcavo-convex structure on a surface thereof.
 10. The light emittingdevice of claim 9, wherein the contact interface has a potential barrierhigher than operational voltage of the light emitting structure.
 11. Thelight emitting device of claim 1, wherein the connection member isspaced apart from the second electrode.
 12. The light emitting device ofclaim 1, further comprising an ohmic contact layer between the firstelectrode and the first semiconductor layer.
 13. The light emittingdevice of claim 12, further comprising a reflective layer between thefirst electrode and the ohmic contact layer.
 14. The light emittingdevice of claim 12, further comprising a current blocking layer betweenthe ohmic contact layer and the first semiconductor layer.
 15. The lightemitting device of claim 14, wherein at least a portion of the currentblocking layer is overlapped with the second electrode in a verticaldirection.
 16. The light emitting device of claim 1, further comprisinga passivation layer on at least one side of the light emittingstructure.
 17. The light emitting device of claim 1, wherein the firstelectrode includes a support member having conductivity.
 18. A lightemitting device comprising: a first electrode including a support memberhaving conductivity; a light emitting structure including a firstsemiconductor layer, an active layer, and a second semiconductor layerover the first electrode; a second electrode over the secondsemiconductor layer; a connection member disposed between the first andsecond semiconductor layers and contacting the first and secondsemiconductor layers, wherein the connection member forms a schottkycontact with one of the first and second semiconductor layers; aninsulating member between a lateral side of the light emitting structureand the connection member; and a passivation layer over the lateral sideof the light emitting structure.
 19. A light emitting device comprising:a first electrode including a support member having conductivity; areflective layer over the first electrode; a protective layer along anouter peripheral portion of a top surface of the reflective layer; anohmic contact layer over the top surface of the reflective layer and aninside side of the protective layer; a light emitting structureincluding a first semiconductor layer, an active layer, and a secondsemiconductor layer over the ohmic contact layer and the protectivelayer; a second electrode over the second semiconductor layer; aconnection member electrically connected to the second electrode anddisposed between the first and second semiconductor layers while forminga schottky contact with the first semiconductor layer; and an insulatingmember between a lateral side of the light emitting structure and theconnection member.